Traditionally, punching bags are formed from an outer shell filled with padding. The bags are usually geometrically shaped (for example, cylindrical, spherical or rectangular) and suspended with chains or the like from an overhead support. The standard cylindrical punching bag, while a useful training tool, does not provide anatomical reference points or lifelike feel and feedback when punched or kicked. Further, in sparring situations an opponent's shoulders are almost never square to the combatant. A right-handed opponent will be turned at an angle with his left shoulder closer to the combatant than his right. Opponents can also either be right-handed or left-handed. Left-handed opponents provide a much different target than do right-handed opponents, primarily due to the different stance which turns the opponent's shoulders opposite direction than those of the right-handed opponent. Traditional bags cannot simulate stance differences based on predominant hand. This limits their usefulness as training tools.
Additionally, different techniques are required for "fighting inside" than are used for normal sparring. "Fighting inside" can loosely be defined as encounters where the opponents are very close to one another or well within the reach of each other. When fighting inside, combatants usually assume a much more defensive posture which involves bending at the waist to give the opponent a smaller target to hit. Prior training bags are unable to simulate this technique and are inadequate for training a fighter to fight inside.
While three dimensional mannequins have existed for years, current mannequins are unsuitable for sparring and training for a variety of reasons. Most traditional mannequins are made from a hard plastic material. Hard plastic mannequins are unacceptable for sparring and training as they could injure the person punching or kicking them. Additionally, the hard nature of the mannequins would not simulate the feel of striking a human body.